When plastic parts need to be secured together, especially in automotive applications, it is often times desirable to use pin fasteners such as push pins rather than screws to make the assembly easier, simpler, less costly and more cosmetically pleasing to the OEM design studio and consumer. A typical push pin is illustrated at reference numeral 10 in FIGS. 3 and 4.
Such a push pin 10 is typically used with a hollow connector portion 12, commonly called a "dog house", which is integrally formed on an inner surface of one of the plastic parts such as a plastic interior trim panel, generally indicated at 14. The trim panel 14 includes a plastic main section generally indicated at 16, and a plastic auxiliary or "flag" section, generally indicated at 18. Use of such "dog houses" 12 and associated push pins 10 produce hidden attachment mechanisms for the plastic parts.
It is generally not difficult to form the connector portions 12 on an inner surface 20 of the main section 16. However, for tooling reasons, such a "dog house" or connector portion typically cannot be formed on an inner surface 22 of the flag section 18. Specifically, the tooling problem is a "locked" lifter or "die lock" condition. Such lifters, which are located within the mold, are used to form the connector portions 12.
Because of this tooling problem, a screw is inserted through an outer surface 24 (FIGS. 3 and 4) of the flag section 18 to fasten the flag section 18 to a corresponding portion 26 of a metallic door inner panel, generally indicated at 28 in FIGS. 3 and 4. However, the outer surface 24 of the flag section 18 is a "Class A" surface. Consequently, the screw mars the outer surface 24.
U.S. Pat. No. 5,501,829 discloses a method of manufacturing trim panels for vehicle doors.
U.S. Pat. No. 5,820,191 discloses a structural inner-door panel for a vehicle that is monolithic and molded as a single piece of polymeric material.
U.S. Pat. No. 5,603,548 discloses an automobile door having an interior trim panel that is connected to a rigid inner structure.
U.S. Pat. No. 5,584,144 discloses a motor vehicle door having an inner panel including an integral mounting base for fastening the bottom of a door pocket to the panel.
U.S. Pat. No. 5,529,370 discloses a trim panel mounting assembly including a trim panel bracket and a support bracket.
U.S. Pat. No. 5,419,606 discloses a trim panel having pins for attaching it to a door panel.
U.S. Pat. No. 4,949,508 discloses a door assembly having a trim panel that is secured by pins.
U.S. Pat. No. 4,845,894 discloses a method for mounting an outer skin to an inner panel of a vehicle door.